LONDON, July 8 (Reuters) - European stocks rebounded on Wednesday after sliding at the start of the week as euro zone members gave Greece more time to come up with a deal to avoid having to leave the euro.

British bank Barclays and Swiss pharmaceuticals group Novartis were among the best performers, with investors welcoming Barclays' decision to dump its chief executive while Novartis got a boost from regulators.

European shares fell at the start of the week after Greek voters rejected austerity measures imposed on the country as part of a bailout programme, while a stock market sell-off in China has put further pressure on markets.

Some investors remain confident Greece may reach a deal to stay in the euro zone, while others said cash and liquidity from the European Central Bank (ECB) could limit any hits to broader European markets if Greece did leave the euro.

Greek Prime Minister Alexis Tsipras assured the European Parliament on Wednesday that he would deliver sweeping reform proposals this week to secure a bailout funding deal that can keep Greece in the euro zone.

"Markets are up on the realisation that this weekend there will probably come an end to the Greek saga, one way or another. Markets are probably priced for a Grexit, but one where contagion may be limited," said Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets in Brussels.

"In the meantime, commodity-related shares are in a downtrend, pressured by the sharp sell-off in the Chinese stock market. This will eventually lead to a massive buying opportunity, but it is clearly too early to jump back in."